Dietary sodium intake and sodium load is associated with arterial stiffness in children and young adults

OBJECTIVE: The aim of this study was to examine the association of sodium intake (g/day) and sodium load (Na-L; mg/kcal/day) on arterial stiffness in youth. METHODS: A cross-sectional analysis of 723 youth enrolled in a study evaluating the cardiovascular effects of obesity and type 2 diabetes mellitus (T2DM). Three measures of arterial stiffness were evaluated: brachial distensibility (BrachD), carotid-femoral pulse wave velocity (PWVcf) and augmentation index (AIx). Three-day diet histories yielded mean daily sodium and calorie intake. Youth were divided into Na-L tertiles: Low (≤1.67 mg/kcal per day); Medium (1.68--1.98 mg/kcal per day) and High (>1.98 mg/kcal per day). General linear models adjusting for demographics, % body fat, T2DM and SBP z-score evaluated the independent association of Na-L with arterial stiffness. RESULTS: Mean age was 17.9 years (10-24 years), 35% male, 59% nonwhite and 31% T2DM. Mean (±standard deviation) dietary intake was calories = 2074 (±797) kcal/day; Na = 3.793 (±1567) g/day; Na- = 1.86 (±0.753) mg/kcal per day. With higher levels of dietary Na intake and Na-L, measures of arterial stiffness worsened: BrachD decreased (Na intake: beta = -0.09, P = 0.003; Na-L: beta = -0.28, P < 0.0001), PWVcf increased (Na intake: beta = 0.07, P = 0.007; Na-L: beta = 0.21, P < 0.0001) but AIx did not change (Na intake: beta = -0.4, P = 0.2; Na-L: beta = 0.89, P = 0.11). In multivariable analysis, High Na-L was independently associated with BrachD, PWVcf and AIx (P < 0.05 for all), with age modifying the association of High Na-L with PWVcf and AIx. CONCLUSION: Sodium intake and load are associated with arterial stiffness, a preclinical measure of CVD, among a paediatric population. Paediatricians should stress healthy dietary choices to reduce accelerated vascular ageing.